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Pararobertsite Mineral Data

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General Pararobertsite Information

Help on Chemical  Formula: Chemical Formula: Ca2Mn+++3(PO4)3O2•3(H2O)
Help on Composition: Composition: Molecular Weight = 615.93 gm
   Calcium     13.01 %  Ca   18.21 % CaO
   Manganese   26.76 %  Mn   38.45 % Mn2O3
   Phosphorus  15.09 %  P    34.57 % P2O5
   Hydrogen     0.98 %  H     8.77 % H2O
   Oxygen      44.16 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca2Mn3+3(PO4)3O2•3(H2O)
Help on Environment: Environment: Rare secondary mineral in a complex zoned granite pegmatite.
Help on IMA Status: IMA Status: Approved IMA 1989
Help on Locality: Locality: Tip Top mine, 8.5 km southwest of Custer, Custer Co., South Dakota, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek para, for near, and its relation to robertsite.
Help on Name Pronunciation: Name Pronunciation: Pararobertsite + Pronunciation Say PARAROBERTSITE
Help on Synonym: Synonym: ICSD 89712
  PDF 45-1440

Pararobertsite Image

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Comments: SEM image of a group of pararobertsite crystals illustraing the typical habit. (CanMin, v27:451).
Location: Tip Top pegmatite, Custer County, South Dakota, USA. Scale: Scale Bar 100 µm.
© Canadian Mineralogist

Pararobertsite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.6656:1:0.8362
Help on Cell Dimensions: Cell Dimensions: a = 8.825, b = 13.258, c = 11.087, Z = 4; beta = 101.19° V = 1,272.54 Den(Calc)= 3.21
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 8.69(1), 2.884(0.6), 5.66(0.6),

Physical Properties of Pararobertsite

Help on Cleavage: Cleavage: {100} Perfect
Help on Color: Color: Bronze, Yellow, Dark red.
Help on Density: Density: 3.22
Help on Diaphaneity: Diaphaneity: Transparent
Help on Hardness: Hardness: 2 - Gypsum
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: brown red

Optical Properties of Pararobertsite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.018 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2523,KPDmeas= 0.2516,KC= 0.2471
Ncalc = 1.79 - 1.8
Help on Optical Data: Optical Data: Biaxial (-), a=1.79, b=1.81, g=1.83, bire=0.0400, 2V(Calc)=88, 2V(Meas)=84.

Calculated Properties of Pararobertsite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.16 gm/cc
note: Specific Gravity of Pararobertsite =3.22 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0003891242
Boson Index = 0.9996108758
Help on Photoelectric: Photoelectric: PEPararobertsite = 9.13 barns/electron
U=PEPararobertsite x rElectron Density= 28.83 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Pararobertsite is Not Radioactive

Pararobertsite Classification

Help on  Dana Class: Dana Class: (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
  (42.08)where (AB)7 (XO4)4 Zq � x(H2O)
  (42.08.05)Kolfanite Group Kolfanite Ca2Fe3O2(AsO4)3•2(H2O) A2/a 2/m Pararobertsite Ca2Mn3(PO4)3O2•3(H2O) P 21/c 2/m Sailaufite! Ca2Mn3O2(AsO4)2(CO3)•3(H2O) Cm m
Help on  Strunz Class: Strunz Class: 08.DH.30 08 - PHOSPHATES, ARSENATES, VANADATES
  08.D - Phosphates, etc
  08.DH -With large and medium-sized cations, (OH, etc.):RO4 < 1:1
08.DH.30 Arseniosiderite Ca2Fe3(AsO4)3O2•3(H2O) A2/a 2/m
08.DH.30 Pararobertsite Ca2Mn3(PO4)3O2•3(H2O) P 21/c 2/m
08.DH.30 Kolfanite Ca2Fe3O2(AsO4)3•2(H2O) A2/a 2/m
08.DH.30 Lunokite (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2(OH)•4(H2O) P bca 2/m 2/m 2/m
08.DH.30 Robertsite Ca6Mn9(PO4)9O6(H2O)6•3(H2O) A2/a 2/m
08.DH.30 Mitridatite Ca2Fe3(PO4)3O2•3(H2O) A2/a 2/m
08.DH.30 Sailaufite! Ca2Mn3O2(AsO4)2(CO3)•3(H2O) Cm m

Other Pararobertsite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Am.Min.,Vol.75,p1211,1990) OPTIC PROP.(Am.Min.,Vol.75,p1211,1990)
Help on See Also: See Also: Links to other databases for Pararobertsite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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Dana No: Strunz No: 08.DH.30





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